(1) Field of Invention
This invention relates generally to masonry structures, and more particularly, to post-construction reinforcement and retrofitting of masonry or foam core structures exposed to extreme wind and/or seismic loading events.
(2) Background
Masonry structures predominate in residential and light commercial construction. In the case of masonry construction, the structure should be protected from uplift, shear, and overturning forces developed by wind or seismic activity. In the United States, the amount of wind and seismic activity differs with geographical location, as is designated by building codes for these areas. In many structures, reinforcing concrete masonry unit (CMU) walls resists these forces. In new construction, this is accomplished by filling vertical cells of the masonry wall with concrete and steel reinforcing bars at a given spacing. The number of reinforced cells and the strength of concrete and steel used will vary depending on the severity of the wind and/or seismic conditions in the locality of the structure, and the structure's geometry.
In many instances, the steel reinforcing is installed during the foundation and masonry installation. Steel is installed into the foundation footings as required by the loads and extends upward beyond the footings approximately two to three feet. The CMUs are then installed over the steel bars so that the steel bars are in the center of the cell (or void within the masonry unit). After the CMU wall is constructed, additional steel that extends from the foundation to the top of the wall is installed. Next, concrete is poured into the cell around the steel bars.
In existing masonry structures, it is inconvenient and sometimes impossible to install a similar system that incorporates steel reinforcement tied into the foundation or footers. Once a structure has been built, the foundation is generally inaccessible to subsequent construction additions without requiring significant time and expense. There is a need for a structural reinforcing system that resists for uplift, shear, and overturning loads that is cost efficient, installed after the foundation and CMUs have already been constructed.
The present invention meets these needs by providing a simplified, cost-effective structural system that is installed after installation of the foundation and masonry wall.